Air duct cleaning in hospitals

Which guidelines apply to ventilation ducts in a hospital?

In the Netherlands there is no single legal provision for hospitals that says how often a duct must be cleaned. The requirements come from a stack of documents that together form the framework. The SRI is the successor to the WIP guidelines for infection prevention; eight parties contribute to it, including NVZ, VHIG, ActiZ and UMCNL. For operating theatres, the air handling guideline is leading, and the Working Conditions Decree (Arbobesluit) applies to all workplaces.

Why EN 15780:2025 does not cover the whole hospital

The European standard for the cleanliness of ventilation systems was revised in 2025. EN 15780:2025 replaces the 2011 version and deals with cleanliness classes, inspection intervals and acceptable cleanliness levels, now including kitchen extraction. Important for healthcare: according to the description of the standard, the new version applies to ventilation systems except industrial, medical and laboratory facilities. For operating theatres and treatment rooms you therefore rely on the healthcare guidelines and your air management plan. For the office section, the main entrance hall or the staff restaurant, EN 15780 can serve as a reference; agree this with your building services consultant.

Many hospitals also look at the German VDI 6022 Part 1 (January 2018 edition). It sets hygiene requirements for air handling installations and specifies a hygiene inspection every 2 years for installations with air humidification and every 3 years without. A Saxon implementation guide for hospitals describes how duct cleanliness is assessed with a dust density measurement by inspectors holding VDI 6022 category A training. A detailed explanation can be found under VDI 6022 ventilation hygiene.

Cleaning operating theatre ventilation: working zone by zone

A hospital runs 24 hours a day, so you work per zone and per air handling unit. The facilities team decides together with the infection prevention department when a section can be taken out of service. A working sequence that works well in practice:

1. Inspect the section with a camera and record the starting situation in photos.
2. Seal off the duct section with duct balloons and cover valves and diffusers with foam caps.
3. Keep the section being cleaned under continuous negative pressure with an extraction unit. If it exhausts inside the building, a HEPA filter of 99.97% at 0.3 µm is required.
4. Clean with rotating brushes or compressed air, working from clean to dirty and towards the extraction point.
5. Check the result with a surface comparison or a gravimetric vacuum test according to NADCA.
6. Put the section back into service and check that the signalling reports no fault.

To see which caps and balloons you need, look at negative pressure HEPA extraction.

Organising inspection and cleaning separately

A common piece of advice from hygiene practice is to assign cleaning and the hygiene inspection to different parties. That way the same party is not judging its own work, which strengthens the objectivity of your file. A hygiene inspection comprises a visual assessment of cleanliness and a microbiological assessment of the supply air and the reference air.

Plan a first inspection at three moments: for a new installation before it is put into use, after a major modification and for an installation that has never been inspected. A compressed air nozzle with a built-in camera, such as the Intelligent Airnozzle for cleaning contractors, also shows you during cleaning what is sitting in bends and corners.

Which equipment suits healthcare duct cleaning?

In a hospital you find ducts of every size: small exhaust ducts above washrooms, medium sized supply ducts to treatment rooms and large main ducts at the air handling units. That calls for more than one machine.

For the main task, the Danduct Clean DC4 for cleaning contractors is the workhorse: you feed the shaft into the duct and the machine automatically rotates left and right. For fibreglass duct board and sheet metal, the US EPA recommends soft brushes. So choose deliberately between soft, normal and Tynex, and first read about ventilation duct brush. All options side by side are on the page with compare duct cleaning kits for cleaning contractors.

How often should you clean or check hospital ventilation ducts?

A fixed cleaning frequency for hospital ducts is not laid down in Dutch law. You work with inspection intervals and clean when the inspection gives reason to.

More about intervals per building type can be found under ductwork cleaning schedule. A practical tip: record each inspection result per zone in the same format, so you can compare the condition of a section over the years and justify why you cleaned it, or why not yet.

Misconceptions about duct cleaning in healthcare

• Clean filters mean clean ducts. Filters catch a lot, but dust also sticks to duct walls. According to the EPA, much of the dust stays stuck to the wall.
• A disinfectant solves it. The EPA has not registered any biocides for use on fibreglass duct board and does not recommend coatings as a routine measure. Mechanical cleaning remains the basis.
• Compressed air only spreads dirt. Without negative pressure that is true. With continuous extraction and sealed sections, compressed air is a usable method.
• New installations are clean. That is why inspection bodies recommend a first hygiene inspection before an installation is put into use.

Each of these misconceptions leads to the same mistake: relying on an assumption instead of an inspection. In a hospital, where the air in patient areas matters so much, the camera image and the measurement are what count, not the appearance of the grille.

Fictional example: a wing with treatment rooms

Fictional example. A hospital wants to tackle a wing with eight treatment rooms and a corridor. The camera inspection shows dust in the supply ducts and a grease layer in the exhaust duct of the pantry. The facilities team plans two nights: night one the supply side with a brushing machine under negative pressure, night two the exhaust side and the pantry. In every room the valves are sealed with foam caps. Afterwards a check follows by a party other than the cleaner, and the photo report goes into the air management plan. The price depends on length, contamination and accessibility and is therefore by quote.

How to estimate the cost of such a project is explained under prices for ductwork cleaning. If you also work for long term care, look at air duct cleaning in care homes. Want to know which machine suits your hospital? You can always duct cleaning equipment quote. Other sectors can be found under ductwork cleaning per industry.